Fluorocarbon based fluids have found widespread use in industry in a number of applications, including as refrigerants, aerosol propellants, blowing agents, heat transfer media, and gaseous dielectrics. Because of the suspected environmental problems associated with the use of some of these fluids, it is desirable to use fluids having low or even zero ozone depletion potential, such as hydrofluorocarbons (“HFC's”). Thus, the use of fluids that do not contain chlorofluorocarbons (“CFCs”) or hydrochlorofluorocarbons (“HCFCs”) is desirable. Additionally, the use of single component fluids or azeotropic mixtures, which do not fractionate on boiling and evaporation, is desirable. However, the identification of new, environmentally-safe, non-fractionating mixtures is complicated due to the fact that azeotrope formation is not readily predictable.
The industry is continually seeking new fluorocarbon based mixtures that offer alternatives to, and are considered environmentally safer substitutes for, CFC's and HCFCs. Of particular interest are combinations or mixtures containing 1,1,1,3,3-pentafluorobutane (HFC-365) and an acid, both having low ozone depletion potentials. (HFC-365 is well known in the art and is described in U.S. Pat. Nos. 5,917,098; 5,395,997; 4,950,364; and 5,208,398, which are incorporated herein by reference.) Such mixtures are the subject of this invention.